00:01
Okay, we are told the chance of getting 22 is 138.
00:05
So that's called the x and getting 22, p of x, that's one chance out of 38.
00:16
Which means not getting 22 must be 37 out of 38, 1 minus 1 over 38.
00:29
Now, this work out then expected winning, winnings here.
00:43
Now, if you get 22, it's a 1 over 38 chance.
00:49
What happens is you will get the money back at plus $245.
00:56
So that will be your winnings if you get the number 22.
01:02
So 2 .45 out of 38 is that's.
01:07
Expected winnings for that.
01:10
Not 22 is 37 out of 38.
01:15
If that occurs, you will lose $7.
01:18
So minus 7.
01:20
So 37 times 7, it can work out.
01:26
It's minus 259 over 38.
01:32
And you can see here slightly bigger than up here.
01:40
That's normal for a casino because in the long run they have to win.
01:45
So just add up these two numbers now.
01:51
I'll add up those two and we're going to get 245 minus 259...